Improvements in or relating to electrical ignition apparatus

686,925. Ignition systems. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Sept. 21, 1951 [Sept. 22, 1950], No. 23337/50. Class 7 (iv). In electrical ignition apparatus comprising for each fixed electrode 12 of a jump-gap distributer, a two electrode spark gap 14 and a con-. denser 15, a connection between the one electrode of the spark gap 14 and the one electrode of the condenser 15 and which is connected to the corresponding fixed distributor electrode 12, the other spark gap electrode being connected to the one electrode of a corresponding surface discharge sparking plug 11 and the other condenser electrode being connected to the other sparking plug electrode, it is arranged that when the moving distributer electrode 51 registers with said fixed electrode 12 sufficient voltage is developed in magneto or induction coil to break down the gap between the registering distributer electrodes whereupon the condenser is charged to a lower voltage than that required to break down the distributer gap, the two electrode spark gap 14 breaks down the condenser discharges through the latter and the corresponding sparking plug 11. The spark gaps 14 break down at a voltage lower than that required to rupture the distributer gap. Inductances such as 16 are connected in each discharge circuit to limit the peak current and increase the duration of each discharge; the inductances may, however, be omitted or inserted elsewhere in the circuit. Electrical values of the components are given.